Stabilizing agent



United States Patent BAA 3,108,356 STAhiLiZiNG AGENT Robert J. Lincoln, Decatur, Ala, assiguor, by mesne assignments, to Monsanto @hernical Company, a corporation of Delaware N0 Drawing. Filed Aug. 23, 1961, Ser. No. 133,321 10 Claims. (til. 23-74) This invention is concerned with the treatment of the nap of woven, non-woven and knitted synthetic fabrics to prevent distortion of the nap due to normal laundry conditions and wearing conditions. More specifically, this invention is concerned with preventing the matting, shedding and pilling of the nap of acrylic fabrics after subjecting these fibers to normal laundering and Wearing conditions.

In the past the nap of synthetic fabrics have been stabilized by the use of salts which were toxic and corrosive; therefore, special and expensive production equipment was necessary to apply these salt solutions to the map of these fabrics. Some of the salts where the pure etal halides such as zinc chloride, lithium bromide and water soluble thiocyanates. These salts were very corrosive to the standard finishing mill equipment. In addition, these salts gave a harsh hand which was very undesirable and effected the color to such an extent that the fabric was unacceptable. While the harsh or crisp hand could be softened, this entailed chemical and mechanical treatment.

An object of this invention is to provide a method by which the nap of synthetic fabrics are stabilized under normal laundering conditions.

Another object of this invention is to provide a stabilizing agent to prevent excess matting, pilling and shedding of the nap of synthetic fabrics.

Another object of this invention is to provide a stabilizing agent for the nap of synthetic fabrics which gives a soft hand.

Another object of this invention is to provide a stabilizing agent for the nap of synthetic fabrics which does not deleteriously affect the color.

Another object of this invention is to provide a stabilizing agent for the nap of acrylonitrile fabrics which renders same free of excessive matting, pilling and shedding under normal laundering and wearing conditions.

Other objects and advantages of this invention will become apparent from the hereinafter detailed description.

The objects of this invention are generally accomplished by applying zinc iluoborate to the nap of synthetic fabrics, either woven, non-woven or knitted by either a padding operation or a spraying technique described more fully hereinafter. In addtion, it was determined that treating the fabric, before napping it and adding the stabilizing salt, with silicone and Aston, which is a polyamine resin such as diethylenetriarnine crossed-linked with polyethylcne glycol diiodide or an epoxy resin, resulted in a soft hand which was acceptable. The silicone penetrated the entire fabric and appeared to prevent the Aston, if used, and the stabilizing agent from penetrating into the main body of the fabric, thus remaining on the nap where it is needed. However, it was not necessary to pro-treat the fabric with silicone and Aston, as described above, in order to secure a soft hand. If, after treatment with the zinc fluob orate the hand is slightly harsh, passing the treated material through a cold calender rendered the hand of acceptable softness.

Most specifically, the nap of the synthetic fabrics may be treated with an aqueous dispersion of silicone in the range of a 0.5 percent to a percent dispersion, with the preferred being a 3 percent dispersion, in conjunction with Aston, as defined herein before, which may be added in hmdfisfi Patented Get. 29, 1%63 addition in the range of a 0.5 percent to a 5 percent solution, with the preferred amount being a 2 percent solution. The use of these two materials prior to'napping and the addition of the stabilizing salt results in a soft hand and color stability. While the stabilizing salt may be used alone and gives satisfactory results, there is a superior result if the fabric is pretreated as described above.

To the nap of synthetic fabrics, either pro-treated as defined above or untreated, was added an aqueous solution of zinc fluoborate in the range of a 0.25 percent to a 10 percent solution, with the preferred percentage being 2 percent. If the pretreatment of the synthetic fabrics is eliminated, then along with this salt is added an aqueous dispersion of a silicone resin, which is in the range of 0.5 percent to a 5 percent dispersion with the preferred percentage being 2, which acted as a softening agent. The fabrics with the treated nap were then heated in a conventional fabric drying apparatus, such as a chain dryer, to evaporate the water and to cure the softening agents; in addition, the stabilizing salt is concentrated at the points of intersection of the fibers in the nap to form a durable bond between themselves. The period of time is in the range of 5 minutes to 15 minutes, with the preferred being 10 minutes, at a temperature of 240 F. to 300 F. with the preferred temperature being 280 F. The mapped fabrics were then withdrawn from the drying apparatus, and it was found that the hand was of acceptable softness and color was unaffected. The stabilizing salt may be added on to the nap by either spraying or padding, which are conventional methods in the textile field.

While this application has been generally directed to synthetic fabrics, it is especially useful in the stabilizing of the nap of fabrics made from fibers of acrylic polymers.

The polymeric materials, which may be employed in the practice of the present invention, are polyacrylonitrile, copolymers, including binary and ternary polymers containing at least percent by weight of acrylonitrile in the polymer molecule, or a blend comprising polyacrylonitrile or copolymers comprising acrylonitrile with from 2 to 50 percent of another polymeric material, the blend having an overall polymerized acrylonitrile content of at least 80 percent by weight. While the preferred polymers employed in the instant invention are those containing at least 80 percent of acrylonitrile, generally recognized as the fiber-forming acrylonitrile polymers, it will be understood that the invention is likewise applicable to polymers containing less than 80 percent aorylonitrile. The acrylonitrile polymers containing less than 80 percent acryloni-trile are useful in forming films, coating compositions, molding operations, lacquers, etc., in all of which applications the alleviation of undesirable color is extremely important.

For example, the polymer may be a copolymer of from 80 to 98 percent acrylcnitrile and from 2 to 20 percent of another monomer containing the O=C linkage and copolymerizable with acrylonitrile. Suitable mono olefin-ic monomers include acrylic, alpha-chloroacrylic and methacrylic acids; the acrylates, such as methylmethacrylate, ethylme-th-acrylate, butylmethacrylate, methoxyniethyl methaorylate, beta-chloroethyl metha'crylate, and the corresponding esters of acrylic and alpha-chloro acrylic acids; vinyl chloride, vinyl fluoride, vinyl bromide, vinyli-dene chloride, l-chloro-l bromo-ethylene; methacryionitrile; acrylamide and methacrylarnide; alphachlo'roncrylarnide; or monoalkyl substitution products thereof; methylvhiyl ketone; vinyl carboxylates, such as vinyl acetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate; N-vinylimides, such as N-vinylphthalimide and N-vinylsuccinimide; methylene malonic esters; itacornc acid and itaconic esters; N-vinylcanbazole; vinyl furane; alkyl vinyl esters; vinyl sulfonic acid; ethylene alpha, beta-dicarboxylic acids or their anhydrides or derivatives, such as diet'nylcitraconate, diethylmesaconate, styrene, vinyl naphthalene; vinyl-substituted tertiary heterocyclic amines, such as the vinylpyridines and mltylsubstituted vinylpyridines, for example, Z-Vinylpyridine, 4-vinylpyridine, Z-methyl-S-Vinylpyridine, etc.; l-vinylimidazole and talkyl-substituted l-vinylimidazoles, such as 2-, 4-, or S-nrethyl-l-vi-nylimi dazole, and other O=C containing polymerizable materials.

The polymer may be a ternary or higher interpolymer, for example, products obtained by the interpolymerization of acrylonitrile and two or more of any of the monomers, other than acrylonitrile, enumerated above. More specifically, and preferably, the ternary polymer comprises acrylonitrile, methacrylonitrile, and 2-vinylpyridine. The ternary polymers preferably contain from 80 to 98 percent of acrylonitrile, from 1 to percent of a vinylpyridine or a l-vinylimidazole, and from 1 to 18 percent of another substance such as methacrylonitrile or vinyl chloride.

The polymer may also be a blend of a polyacrylonitrile or of a binary interpolymer of from 80 to 99 percent acrylonitrile and from 1 to 20 percent of at least one other C=C containing substance with from 2 to 50 percent of the weight of the blend of a copolymer of from 10 to 70 percent of acrylonitrile and from to 90 percent of at least one other C=C containing polymerizable monomer. Preferably, when the polymeric material comprises a blend, it will be a blend of a copolymer of 90 to 98 percent acrylonitrile and from 2 to 10 percent of another mono-olefinic monomer, such as vinyl acetate, which is not receptive to dyestuff, with a sufiicient amount of a copolymer of from 10 to 70 percent of acrylonitrile and from 30 to 90 percent of a vinyl-substituted tertiary heterocyclic amine, such as vinylpyridine or l-vinylimidazole, to give a dyeable blend having an overall vinylsubstituted tertiary heterocyclic amine content of from 2 to 10 percent, based on the weight of the blend.

The following examples are cited to illustrate the invention. They are not intended to limit it in any way. Unless otherwise noted, percentages as expressed in the examples indicate percent by weight.

Example 1 A swatch of napped fabric composed of synthetic, linear acrylonitrile polymers was padded with a 2 percent aqueous solution of zinc fiuoborate along with a 2 percent emulsion of a silicone in water. The swatch was then placed in a drying oven and heated for 10 minutes at a temperature of 280 -F. It was then removed and allowed to cool, after which the swatch was laundered five consecutive times under normal laundering conditions. There was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there was no excessive amount of matting, pilling or shedding.

Example 2 A swatch of napped fabric composed of fibers of 92 percent acrylonitrile and 8 percent vinyl acetate was padded with a 1 percent aqueous solution of zinc fluoborate along with a 2 percent emulsion of a silicone in water. The swatch was then placed in a drying oven and heated for 10 minutes at a temperature of 280 F. It was then removed and allowed to cool, after which the swatch was laundered five consecutive times under normal laundering conditions. There was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there was no excessive amount of matting, pilling, or shedding.

Example 5 A swatch of napped fabric composed of fibers of 92 percent acrylonitrile and 8 vinyl acetate was padded with a 2 percent aqueous solution of zinc fluoborate along with a 4 percent emulsion of a silicone in water. The swatch was then placed in a drying oven and heated for 10 minutes at a temperature of 280 F. It was then removed and allowed to cool, after which the swatch was laundered five consecutive times under normal laundering conditions. There was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there was no excessive amount of matting, pilling or shedding.

Example 4 A swatch of mapped acrylic fabric composed of fibers of a blend of 88 percent of one copolymer of 94 percent acrylonitrile and 6 percent vinyl acetate and 12 percent of another copolymer composed of 50 percent acrylonitrile and 50 percent methyl vinyl pyridine was padded with a 1 percent aqueous solution of zinc fluoborate along with a 3 percent emulsion of a silicone in water. The swatch was then placed in a drying oven for 12 minutes at a temperature of 250 F. It was then removed and allowed to cool, after which the swatch was laundered five consecutive times under normal laundering conditions. There was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there was no excessive amount of matting, pilling or shedding.

Example 5 The exact procedure of Example 4 was repeated except the swatch was heated to 280 F. for 10 minutes with the same end results after laundering five consecutive times.

Example 6 A roll of fabric composed of fibers of synthetic, linear acrylonitrile polymers was continuously padded with a 2 percent aqueous solution of Aston, as defined hereinbefore, and a 3 percent emulsion of a silicone. The fabric was then passed in a continuous movement onto a chain dryer where it was heated within a range of 250 @F. to 280 F. for approximately 10 minutes. It was then passed continuously over a napping machine, for example a Gessmer Double Acting Napper, where the surface of the fabric was raised. Then the napped fabric was continuously passed through a bath composed of a 1.25 percent aqueous solution of zinc fluoborate and passed through a chain dryer for 10 minutes at 280 F. The fabric was then cut into blanket size pieces and laundered five consecutive times under normal laundering conditions. There was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there Was no excessive amount of matting, pilling or shedding.

Example 7 The exact procedure of Example 6 was followed except cept the roll of fabric was composed of fibers of 92 percent acrylonitrile and 8 percent vinyl acetate. The end results were the same after five consecutive launderings.

Example 8 The exact procedure of Example 6 was followed exthe roll of fabric was composed of fibers of a blend of 88 percent of one copolymer of 94 percent acrylonitrile and 6 percent vinyl acetate and 12 percent of another copolymer composed of 50 percent acrylonitrile and 50 percent methyl vinyl pyridine. After the five launderings, there was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there was no excessive amount of matting, pilling or shedding.

Example 9 A roll of fabric composed of fibers of 92 percent acrylonitrile and 8 percent vinyl acetate was continuously padded with a 2 percent solution of Aston, as defined hereinbefore and a 6 percent emulsion of a silicone resin which is a softening agent. The fabric was then passed conthiuously on a chain dryer where it was heated Wlfl'b in a range of 250 F. to 280 F. for approximately 10 minutes. It was then passed continuously over a napping machine, for example a Gessmer Double Acting Napper, where the surface of the fabric was raised. Then the nappled fabric was continuously passed through a bath composed of a 4 percent solution of Zinc fluoborate and a 2 percent emulsion of a silicone resin and passed onto a chain dryer for 10 minutes at 280 F. The fabric Was cut into blanket size pieces and laundered five consecutive times under normal laundering conditions. There was no appreciable change in the soft hand which would affect its commercial acceptability and the color was not affected. In addition there was no excessive amount of matting, pilling or shedding.

The percentages concerning the various solutions in the above examples were all based on the padding and/or treating baths.

With the stabilizing salt of this invention, it is possible to treat napped fabrics composed of the acrylics so that they may be laundered many times and their hand, color and physical properties, such as matting, pulling and shedding, will not be appreciably changed from their original conditions.

Many modifications of the above will be obvious to those skilled in the art without a departure from the inventive concept.

What is claimed is:

1. An article composed of the mapped fabric of fibers of synthetic linear acrylonitrile treated with zinc fiuoborate.

2. The article of claim 1' in which the fabric is composed of fibers of a copolymer of at least 80 percent acrylonitrile and up to percent of another copolymerizable mono-o-lefinic monomer.

3. The article of claim 1 in which the fabric is composed of fibers of a copolymer of 94 percent acrylonitrile and 6 percent vinyl acetate.

The article of claim 1 in which the fabric is com posed of fibers of a blend of 88 percent of one copolymer of 94 percent aorylonitrile and 6 percent vinyl acetate and 12 percent of another :copolymer composed of 50 percent acrylonitrile and 50 percent methyl vinyl pyridine.

5. A method of stabilizing the nap of fabrics composed of fibers of synthetic linear polymers of acrylonitrile, comprising treating the napped fabric with a solution of Zinc fluobonate and drying said treated fabric.

6. A method of a copolymer of stabilizing the nap of fabrics composed of fibers of at least 80 percent acrylonitrile and up to 20 percent of another copolymerizable mono-olefinic monomer comprising treating said napped fabric with a solution of zinc iiuoborate.

7. The method of claim 6 in which the fabric, after napping, is padded with a solution of zinc fluoborate in the range of 0.25 percent to 10 percent, based on the bath, and an aqueous dispersion of a softening agent in the range of 0.5 percent to 5 percent, based on the bath, drying said fabric within a temperature range of 240 F. to 300 F. for a time range of 5 minutes to 15 minutes.

8. The method of claim 6 in which said fabric is treated with a softening agent 'aqueous dispersion in the range of 0.5 percent to 5 percent, based ont-he bath, and an aqueous solution of an anti-static agent in the range of 0.5 percent to 5 percent, based on the bath in a temperature range of 250 F. to 280 for 10 minutes and then said fabric is napped and treated with the zinc fluoborate solution and then dried.

9. A method of stabilizing the nap of fabrics composed of fibers of a copolyrner of 92 percent acrylonitrile and 8 percent vinyl acetate comprising treating said fabric with a 3 percent aqueous dispersion of a silicone resin, based on the bath, and a 2 percent solution based on the bath of a softening agent of a polyarnine resin, passingthis treated fabric through a dryer for 10 minutes at a temperature of 260 F, passing said dried fabric onto a napping machine where the surface of said fabric is raised,

assing said treated and napped dried fabric into a bath composed of a 2 percent solution of zinc fluoborate and a 2 percent dispersion of a silicone softening agent, passing said treated fabric into a dryer heated to 280 F. for 10 minutes and removing said fabric from the drying oven.

10. A method of stabilizing the nap of fabrics composed of fibers of a blend of 88 percent of one copolymer of 94 percent acrylonitrile and 6 percent vinyl acetate and 12 percent of another copolymer composed of 50 percent acrylonitrile and 50 percent methyl vinyl pyridine, comprising treating said fa-bric with an aqueous dispersion of a silicone resin in a range of from 0.5 percent to 5 percent, based on the bath, and an aqueous solution of a polyamine resin in a range of from 0.5 percent to 5 percent, based on the bath, passing this treated fabric through a dryer for from 5 minutes to 15 minutes at a temperature of from 240 F. to 300 F., passing said dried fabric onto a napping machine where the surface of said fabric is raised, passing said treated, napped and dried fabric into a bath composed of an aqueous solution of zinc fluoborate in the range of from 0.25 percent to 10 percent, pass ing said treated fabric into a dryer heated to a temperature of from 240 F. to 300 F. and maintaining said fabric in said dryer for from 5 minutes to 15 minutes and removing said fabric from the dryer.

References Cited in the file of this patent UNITED STATES PATENTS 2,107,528 Feinberg Feb. 8, 1938 

1. AN ARTICLE COMPOSED OF THE NAPPED FABRIC OF FIBERS OF SYNTHETIC LINEAR ACRYLINITRILE TREATED WITH ZINC FLUOBORATE.
 5. A METHOD OF STABILIZING THE NAP OF FABRICS COMPOSED OF FIBERS OF SYNTHETIC LINEAR POLYMERS OF ACRYLINITRILE, COMPRISING TREATING THE NAPPED FBARIC WITH A SOLUTION OF ZINC FLUOBORATE AND DRYING SAID TRATED FABRIC. 